The bid by Comcast to acquire Time Warner Cable would combine America’s two largest cable companies — but there are plenty of hurdles ahead before it can be a $45.2 billion done deal.

Comcast made it official Thursday announcing that it was buying Time Warner Cable in an all-stock deal. The company contends the deal will benefit consumers by creating a company that can deliver new products and services as well as a faster network.

“The combination of Time Warner Cable and Comcast creates an exciting opportunity for our company, for our customers, and for our shareholders,” said Brian L. Roberts, Comcast chairman and chief executive officer. “In addition to creating a world-class company, this is a compelling financial and strategic transaction for our shareholders. Also, it is our intention to expand our buyback program by an additional $10 billion at the close of the transaction.”

Free Press President and CEO Craig Aaron said the deal combining the two would mean higher prices.

“In an already uncompetitive market with high prices that keep going up and up, a merger of the two biggest cable companies should be unthinkable,” he said. “This deal would be a disaster for consumers and must be stopped.”

The Justice Department or the Federal Trade Commission will examine the deal for antitrust concerns, and the Federal Communications Commission will decide if the merger is in the public interest. Comcast is the largest pay-TV company, followed by satellite TV providers DirecTV and Dish. Time Warner rounds out the top four.

Recent deals have been rejected by the federal government. The Justice Department and the FCC said no to AT&T’s attempt to take over T-Mobile — a deal that would have combined the No. 2 and No. 4 wireless operators.

It’s too early to say what antitrust analysis regulators will do or how they will define the marketplace. In the past, cable company unions have passed antitrust muster as long as the combination didn’t eliminate a cable competitor in a local market.

John Bergmayer, Public Knowledge’s senior staff attorney, added: “Comcast cannot be allowed to purchase Time Warner Cable. Antitrust authorities and the FCC must stop it.”

The deal is already drawing the interest of key lawmakers. The leaders of the Senate Judiciary Committee’s antitrust panel said they plan to hold a hearing on the transaction.

“This proposed merger could have a significant impact on the cable industry and affect consumers across the country,” Sen. Amy Klobuchar (D-Minn.), the panel’s chairwoman, said in a statement. The hearing will “carefully scrutinize the details of this merger and its potential consequences for both consumers and competition,” she said.

Comcast offered some early concessions to regulators, including a pledge to extend controversial network neutrality rules to the Time Warner Cable systems it acquires as part of the deal.

A federal appeals court earlier this year rejected some of the FCC’s core net neutrality rules barring companies from blocking or discriminating against certain kinds of Web traffic, but Comcast is bound by the rules under a consent decree reached with the government when the company took over NBC Universal in 2011.

“The FCC’s Open Internet order, and in particular its no-blocking and non-discrimination provisions, will continue to be binding not only in the Comcast territories but now in the Time Warner footprint as well,” Comcast Executive Vice President David Cohen said in a conference call.

Comcast executives also said they plan to divest cable systems with about 3 million customers.

Roberts contends that the deal won’t change the field of play in the cable market because there is very little overlap between the two companies. Comcast’s national market share will remain below 30 percent.

But he added that the deal is attractive because it would add big media markets to the company portfolio.

“Its systems are in premier markets including New York, Los Angeles and Dallas,” he said. “This transaction will allow us to extend the benefits of scale to bring technically superior video and high-speed capabilities to Time Warner’s cable customers.”